Electrospray ionization mass spectrometric solvate cluster and multiply charged ions: a stochastic dynamic approach to 3D structural analysis

Abstract

The data analyzed in this paper are on quantitative and 3D structural determination of ionic ensembles and multiply charged solvates ions of type [(Cl)(H2O)x(H3O)y(CH3CN)z]+, [(Cl)(O2)x(CH3OH)y(NH4)z]+, [(O2)x(H2O)(H3O)(CH3CN)]+n and [(Cl)(H2O)2(H3O)(CH3CHN2)]+ observable under electrospray ionization conditions in presence of ZnII-ion containing metal-organics, where x = y = z = 1–3 are the number of molecules, respectively, ions participating into each of the interacting ensemble, while “n” denotes the number of interacting ensembles forming the more complex ionic clusters. The major theoretical problem we have to deal with is the applicability of our more recently developed stochastic dynamic concept and formulas connecting among the mass spectrometric variable intensity, the so-called stochastic dynamic diffusion parameters (DSD), the temperature (T) and the analyte concentration in solution to such challenging molecular/ionic systems from the perspective of molecular structure. The DSD parameters of analyte ions correlate linearly with the so-called quantum chemical diffusion parameters (DQC) according to the Arrhenius’s theory. The work has demonstrated persuasively that these equations are capable of providing reliable analytical information about so complex ensembles of interacting species. It shows their significant advantages as analytical approaches, amongst other rival concepts, to quantify the mass spectrometric outcome intensity highly accurately, selectively, precisely and sensitively. The thermodynamics parameters of common reactions of the following ionic species observable under electrospray ionization experimental conditions of some tetrachlrozinc(II) complex ions of metal-organics are examined. These are the ions [(Cl)(H2O)(H3O)2(CH3CN)3]+ (m/z 214/216), [(Cl)(H2O)(H3O)2(CH3CN)2]+ (m/z 173/175), [(Cl)(H2O)2(H3O)2(CH3CN)]+ (m/z 150/152), [(Cl)(H2O)(H3O)2(CH3CHNH]+ (m/z 134/136,) [(Cl)(H2O)2(H3O)(CH3CHNH2]+, [(Cl)(H2O)(H3O)2(CH3CN]+ (m/z 132/134,) [(Cl)(H2O)2(H3O)2(CH3CN]+ (m/z 183/185), [(CH3OH)(H2O)5(NH4)(CH3CN)3]+3 (m/z 263,) and [(CH3OH)(H2O)(H3O)(CH3CN)]+31 (m/z 110,) respectively.